Department of Ophthalmology, School of Medicine, 2. Department of Epidemiology, School of Public Health, and 3

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1 Journals of Gerontology: MEDICAL SCIENCES Cite journal as: J Gerontol A Biol Sci Med Sci May;68(5): doi: /gerona/gls185 The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please journals.permissions@oup.com. Advance Access publication September 14, 2012 A Population-Based Examination of the Visual and Ophthalmological Characteristics of Licensed Drivers Aged 70 and Older Cynthia Owsley, 1 Gerald McGwin Jr., 1,2,3 and Karen Searcey 1 1 Department of Ophthalmology, School of Medicine, 2 Department of Epidemiology, School of Public Health, and 3 Department of Surgery, Section on Trauma, Burns, and Surgical Critical Care, School of Medicine, University of Alabama at Birmingham. Address correspondence to Cynthia Owsley, PhD, Department of Ophthalmology, University of Alabama at Birmingham, 700 S. 18th Street, Suite 609, Birmingham, AL owsley@uab.edu Background. Safe driving performance depends on visual skills yet little is known about the prevalence of vision impairments in older drivers and the eye conditions that cause them. This study is a population-based examination of the prevalence of vision impairment and major ophthalmological conditions among drivers aged 70 and older. Methods. The source population was a random sample of 2,000 licensed drivers aged 70 and older residing in north central Alabama. All had driven within the past 3 months. Binocular visual acuity and contrast sensitivity were assessed. The Useful Field of View subtest 2 and Trails B assessed visual processing speed. Ophthalmological diagnoses for cataract, intraocular lens placement, glaucoma, diabetic retinopathy, age-related macular degeneration, and diabetic retinopathy were obtained through medical records from the most recent eye examination. Results. Ninety-two percent of drivers had visual acuity of 20/40 or better; only two drivers (0.1%) had acuity worse than 20/100. Ninety-three percent had normal contrast sensitivity ( 1.5). About 40% had slowed visual processing speed (44%, Useful Field of View; 38%, Trails B). The most common eye condition was cataract, with more than half having cataract in one or both eyes (56%); yet by the 80s and 90s, the prevalence was low, with most drivers having undergone cataract surgery and intraocular lens placement. Conclusions. This population-based study suggests that serious impairment in central vision visual acuity or contrast sensitivity is rather uncommon in older drivers; however, slowed visual processing speed is common. Key Words: Aging Driving Vision impairment Eye disease Received February 19, 2012; Accepted July 27, 2012 Decision Editor: Stephen Kritchevsky, PhD Several chronic eye diseases of adulthood are common among the older adult population in the United States. Recent estimates based on epidemiological studies indicate that about 10 million older adults in the United States have age-related macular degeneration that can cause deficits in acuity and contrast sensitivity in central vision (1). Approximately 2.5 million adults aged 40 and olderhave glaucoma that leads to peripheral vision loss and in more severe forms, central vision loss (2), and about 4 million have diabetic retinopathy that impairs many aspects of vision (3). The increased optical density (ie, opacity) of the crystalline lens is inevitable in all aging eyes (4). Functionally significant cataract is common with an estimated 20.5 million adults in the United States having cataract in one or both eyes (5). The numbers of older Americans who have these conditions is expected to increase over the next 10 years given the aging of the baby boom generation. Driving is inarguably a visual task, and certain types of visual sensory and higher order visual processing impairments in older drivers have been linked to impaired driving performance and increased motor vehicle collision (MVC) risk (6). The high prevalence of vision-impairing eye conditions among older adults, and other aging-associated functional problems, has caused societal concern about the safety of older drivers (7 9). Yet, there is little known on a population basis about how pervasive visual impairments are in older drivers, as well as the eye conditions that cause them. Some older adults voluntarily stop driving because of visual problems, either on their own or at the urging of their families, friends, physicians, and/or other health care providers (10 12). Others do not get their licenses renewed 567

2 568 OWSLEY ET AL. because they do not meet their state s vision standards for licensing. Thus, relying on population-based studies about the prevalence of eye disease and vision impairment in the overall older adult population is inadequate for estimating eye disease and vision impairment rates for the driver segment of this population, and could lead to an exaggeration of the percentage of older drivers with eye disorders and vision impairment who are actually behind the wheel. The purpose of this study is to conduct a population-based examination of licensed drivers aged 70 and older to determine the prevalence of vision impairment and the common ophthalmological conditions of later adulthood (age-related macular degeneration, glaucoma, diabetic retinopathy, and cataract). In characterizing vision, the researchers have examined both visual sensory function as well as higher order visual processing characteristics. Methods This study was approved by the Institutional Review Board of the University of Alabama at Birmingham. The source population consisted of adults aged greater than or equal to 70 years who resided in Jefferson County, Alabama or the border areas of contiguous counties. Potential participants were randomly identified from contact information available through a list of persons obtained from a direct marketing company (Pinpoint Technologies, Tustin, CA). The researchers then confirmed driver s license status through the Alabama Department of Public Safety, and eliminated those from the target population who did not hold Alabama licenses. Potential participants were randomly selected from the final list, received a letter, and telephoned to confirm eligibility. Persons who stated they had an Alabama license and had driven within the last 3 months, were aged 70 and older, and spoke English were invited for a study visit. Participants were enrolled between October 2008 and August The target sample for enrollment was 2,000 drivers. Following written informed consent, the study visit had two parts. The first part consisted of questionnaires. A trained interviewer administered a demographic review (age, gender, race/ethnicity, education, and marital status), a general health questionnaire about the presence versus absence of chronic medical conditions (ie, has a doctor ever told you that you have... ) (13), questions about smoking (14) and alcohol use (15), the Mini-Mental State Examination (MMSE) (16), and asked how many days the person drove in a typical week in recent months (17). The second part of the visit consisted of visual screening tests. Both visual sensory tests for central vision and visual processing speed tests were included. The specific tests described later were selected because of their established relevance to driving performance, licensure, or driver safety in older drivers (6,18 21). For all testing, measurements were made under habitual correction if they had one, that is, participants wore whatever spectacles or contact lenses they would normally wear for that viewing distance. All tests were administered under binocular viewing unless noted. (a) Visual acuity for letters was assessed using the Electronic Visual Acuity system (22), and expressed as log minimum angle resolvable. (b) Contrast sensitivity was assessed using the Pelli Robson Contrast Sensitivity Chart (23), and was scored by the letter-by-letter method (24). (c) Visual processing speed under divided attention conditions was examined by the UFOV subtest 2 (Visual Awareness Research Group, Punta Gorda, FL) (20). This screening test, administered on a computer, estimates the amount of time in milliseconds that a person needs to discriminate which of two test targets is presented at fixation in central vision, while simultaneously identifying the location of a peripheral target in the 10 radius field. (d) Visual processing speed while dividing attention was also assessed using the Trails B test (25), a paper and pencil test that also relies on executive control abilities. These visual processing speed tests can also considered as cognitive tests because they involve higher order information processing components. The presence of common chronic age-related eye conditions was determined by obtaining a copy of participants most recent eye examination performed by an ophthalmologist or optometrist. Participants completed a signed medical record release authorizing the study to obtain these records. An experienced coder of eye medical records recorded whether the participant had diagnoses of cataract, age-related macular degeneration, diabetic retinopathy or diabetic macular edema, glaucoma, or had an intraocular lens (IOL) (meaning that cataract surgery had been performed). The diagnoses were coded separately for each eye. The coder was masked to all other data collected on the participant, and agreement with a second coder was high (91.4%). Chi-square and t tests were used to compare demographic, health, vision, and driving characteristics across age groups (ie, those in their 70s, 80s, and 90s). p values of.05 (two-sided) were considered statistically significant. Results A total of 18,544 persons were contacted by a letter describing the study. Of those who were sent letters, 61% (11,267 of 18,544) were successfully reached by telephone. Of those reached by telephone, 30% (3,412 of 11,267) agreed to answer questions from the eligibility screener. Of those who completed the telephone screener, 70% (2,389 of 3,412) were eligible. Eighty-four percent (2,000 of 2,389) of persons meeting eligibility criteria consented to participate. The eligible persons who participated were on average 1 year younger (77 years old) than those who declined participation (78 years old) (p <.0001) and were also more likely to be male participants (p <.0001).

3 OLDER DRIVERS, VISION, AND EYE CONDITIONS 569 Table 1. Demographic Characteristics and Days of Driving Per Week of the Sample of Older Drivers Aged 70 y Characteristic Participants ranged in age from 70 to 98 years old. As shown in Table 1, 72% of the sample was in the 70s, 26% in the 80s, and 2% in the 90s. In each decade, men were slightly more common than women (~56% vs ~44%). Eighty-two percent of the sample was white, 17.5% African American, and 0.5% of other races/ethnicities. This breakdown manifested within each decade of age, although there was a nonsignificant disproportionate number of whites in the 90s as compared with African Americans. Drivers in their 70s and 80s were split about evenly between those who were married versus not (either single, separated, divorced, or widowed), whereas most drivers in their 90s (70%) were not married. The vast majority of drivers (93.3%) had completed the equivalent of a high school education or beyond. Approximately 70% 75% of drivers in their 70s and 80s reporting driving at least 5 days per week; for those in their 90s, just more than half (57%) drove at least 5 days per week. Approximately 50% of the sample had three or fewer medical comorbidites (Table 2). This was the case for those in their 70s and in their 90s, but those in their 80s had a lower rate of less than or equal to 3 comorbidities at 40%. In general the medical comorbidity distribution for those in the 90s was shifted toward fewer comorbidities as compared with those in younger decades of age. Medical records from the most recent eye examination were obtained for 95% (1,899 of 2,000) of participants; Age y old y old y old p Value All Ages n, % n = 1,433 n = 527 n = 40 Gender.8848 Men 814 (56.8) 293 (55.6) 23 (57.5) 1,130 (56.5) Women 619 (43.2) 234 (44.4) 17 (42.5) 870 (43.5) Race.5626 African American 258 (18.0)) 90 (17.1) 3 (7.5) 351 (17.5) White 1,166 (81.4) 437 (82.9) 37 (92.5) 1,640 (82.0) Other 9 (0.6) 0 (0) 0 (0) 9 (0.5) Marital status <.0001 Married 847 (59.1) 233 (44.2) 12 (30) 1,092 (54.6) Single 89 (6.2) 44 (8.4) 1 (2.5) 134 (6.7) Separated 2 (0.1) 1 (0.2) 0 (0) 3 ( (0.1) Divorced 132 (9.2) 19 (3.6) 1 (2.5) 152 (7.6) Widowed 363 (25.2) 230 (43.6) 26 (65.0) 619 (31.0) Education.0014 Less than high school graduate 82 (5.8) 48 (9.1) 3 (7.5) 133 (6.7) High school graduate or general 414 (28.9) 128 (24.3) 8 (20.0) 550 (27.5) equivalency diploma 1 4 y of college 714 (49.9) 277 (52.6) 27 (67.5) 1,018 (50.9) Postgraduate degree 222 (15.5) 74 (14.0) 2 (5.0) 298 (14.9) Days driven per week (6.2) 40 (7.6) 5 (12.5) 135 (6.8) (18.8) 115 (21.8) 12 (30) 397 (19.9) (23.0) 117 (22.2) 9 (22.5) 456 (22.8) (51.6) 255 (48.4) 14 (35.0) 1,012 (50.6) Mean (SD) 5.7 (1.7) 5.5 (1.8) 4.9 (2.0) 5.6 (1.7) 71% of these examinations were within 1 year of the enrollment date, and 87% were within 2 years. Reasons for not obtaining medical records on the remaining 5% (101 of 2,000) were the participant declined to sign the medical release (2), participant could not identify an eye care provider they had seen (59), participant signed the release but the eye care provider had no record on file for that person (38), or the eye care provider never sent us the record despite the researchers sending the medical release and repeated requests (2). Half of all drivers in the sample had cataract in one or both eyes, and half had IOLs in one or both eyes. There were noteworthy differences by decade however. Sixty-four percent of drivers in the 70s had cataract, with this percentage decreasing to 39% in the 80s and 26% in the 80s. Correspondingly, the percentage of those with an IOL in one or both eyes (meaning they had undergone cataract surgery) trended in the opposite direction by age, being lowest in the 70s to 39%, increasing in the 80s to 66%, and in the 90s to 85% of drivers. With respect to glaucoma and related conditions, 18% of the sample had been diagnosed with glaucoma, being glaucoma suspects, or having ocular hypertension. The percentage of drivers with glaucoma-related conditions increased with age from 17% in their 70s to 36% in their 90s having these conditions. The prevalence of age-related macular degeneration also increases with each decade of age rising from 16% in the 70s to 26% in the 90s. Diabetic

4 570 OWSLEY ET AL. Table 2. Health Characteristics of the Sample of Older Drivers Aged 70 y Including Number of Medical Comorbidities, Eye Conditions, Smoking and Alcohol Use, and Mental Status Characteristic retinopathy and diabetic macular edema were less common than the other chronic eye conditions of aging and also had opposite trends, being more common among drivers in their 70s (4%) than in their 80s (2%), and not present in any of the participants in their 90s. A low proportion of drivers in the sample were current smokers (5%), with none in the 90s being smokers. The extent of alcohol use was similar across all three decades. About 47% reported not using alcohol at all and 43% reported having between 1 7 drinks per week. Approximately 4% said that they had 15 or more drinks per week. The vast majority of the sample (98%) had MMSE scores greater than or equal to 24; of those who had scores greater than or equal to 24, 73.3% had scores from 28 to 30. The percentage of those with scores less than 24 was higher in the 80s (5%) and 90s (5%) compared with the 70s (0.1%). Just over half the sample (56.7%) had visual acuity of 20/20 or better (Table 3). More than 90% of the sample had visual acuity of 20/40 or better. The distribution of visual acuity was displaced to worse values with advancing decade of age, however, even in the 90-year-olds, 70.7% had acuity of 20/40 or better. Only two drivers in the sample (0.1%) had acuity worse than 20/100 (both were 20/200). Age y old y old y old p Value All Ages n, % No. of medical comorbidities (12.6) 41 (7.8) 4 (10) 226 (11.3) (37.0) 175 (33.2) 16 (40) 721 (36.1) (34.5) 187 (35.5) 13 (32.5) 694 (34.7) (12.4) 94 (17.8) 6 (15.0) 277 (13.9) (3.1) 26 (4.9) 1 (2.5) 72 (3.6) 10 6 (0.4) 4 (0.8) 0 (0.0) 10 (0.5) Eye conditions* Cataract 867 (63.8) 196 (39.0) 10 (25.6) < ,073 (56.5) Glaucoma 234 (17.2) 99 (19.7) 14 (35.9) (18.3) Diabetic retinopathy or diabetic macular edema 56 (4.1) 8 (1.6) 0 (0) (3.4) Age-related macular degeneration 219 (16.1) 114 (22.7) 10 (25.6) (18.1) Intraocular lens 523 (38.5) 333 (66.3) 33 (84.6) < (46.8) Smoking Never 668 (46.7) 252 (47.9) 24 (61.5) (47.3) Previous 682 (47.7) 261 (49.6) 15 (38.5) 958 (48.0) Current 80 (5.6) 13 (2.5) 0 (0) 93 (4.7) Alcohol use, drinks per week None 675 (47.1) 253 (48.0) 19 (47.5) (47.4) (43.0) 224 (42.5) 16 (40.0) 856 (42.8) (5.8) 34 (6.5) 3 (7.5) 120 (6) (4.1) 16 (3.0) 2 (5.0) 77 (3.9) Mean (SD) 2.1 (4.8) 2.0 (4.5) 1.9 (4.0) 2.1 (4.7) Mental status (98.6) 502 (95.3) 38 (95.0) 1,953 (97.6) (1.4) 24 (4.6) 2 (5.0) 45 (2.3) <17 1 (0.1) 1 (0.2) 0 (0) 2 (0.1) Mean (SD) 28.4 (1.7) 27.7 (2.3) 27.1 (1.7) 28.2 (1.9) Note: SD = standard deviation. *In at least one eye. The vast majority of drivers in the sample (93.4%) had contrast sensitivity scores of 1.5 or better. The distribution of contrast sensitivity was displaced to worse scores with increasing age. About 33% of drivers in the 90s had contrast sensitivity scores worse than 1.5, whereas less than 7% of drivers in the 70s and 80s had scores less than 1.5. Visual processing speed as measured by the UFOV subtest 2 or Trails B was in the normal range (<150 ms for UFOV subtest 2; <2.47 minutes for Trails B) for just more than half the sample (UFOV, 56.3%; Trails B, 62.2%). Both visual processing speed tests showed a slowing in processing speed with advancing age. For example, UFOV scores were in the slowest processing speed category for 49% of drivers in the 90s, whereas only 7.4% of drivers in their 70s had scores in the slowest category. Similar trends were present for Trails B. Half of drivers reported that they drove 7 days per week (50.6%) and over a distance of more than 88 miles per week (49.7%). The estimated number of trips drivers made per week had wide individual variability. About two thirds of the sample (68%) drove to four or fewer different places per week. Drivers on average reported driving 9,528 miles per year, with half the drivers driving less than or equal to 7,200

5 OLDER DRIVERS, VISION, AND EYE CONDITIONS 571 Table 3. Visual Characteristics of the Sample of Older Drivers Aged 70 y Including Visual Acuity, Contrast Sensitivity, and Visual Processing Speed Characteristic Age y old y old y old miles per year. All driving exposure variables had lower values with advancing decade of age, except for the number of days driven per week, which did not change with age. Discussion With increases in the population aged 70 and older, there has been widespread concern in the United States about the safety of older adults who drive (6 9,26,27), because visual functional impairments and eye conditions are common in this population compared with younger adults (1 3,5). Yet, results from this population-based study suggest that concerns that many older drivers have visual sensory impairments are highly exaggerated when viewed against the reality of the situation. Ninety-two percent of drivers in our sample had habitual visual acuity of 20/40 or better, with 20/40 being a common vision standard for licensure in various states. This means that the vast majority of the sample would be viewed as safe drivers according to vision standard policies for licensure. Of the remaining 8%, all but two drivers had visual acuity in the 20/50 to 20/100 range. Since several decades of research indicate that drivers with visual acuity between 20/50 and 20/100 do not have an elevated crash risk (6), some states (eg, Maryland and Iowa) are now allowing licensure for such drivers if they pass more detailed driving evaluations. The remaining two drivers in this sample had visual acuity worse than 20/100 but better than 20/200, which represents only 0.01% of the entire sample. The results with respect to contrast sensitivity are p Value All Ages n, % Visual acuity (OU) < /20 or better 878 (61.3) 243 (46.2) 11 (28.2) 1,132 (56.7) Wt 20/20 to 20/ (31.9) 231 (43.9) 17 (42.5) 705 (35.3) Wt 20/40 to 20/ (6.7) 51 (9.7) 12 (30.0) 159 (8.0) Wt 20/100 to 20/200 1 (0.1) 1 (0.2) 0 (0.0) 2 (0.1) Mean (SD), logmar 0.04 (0.13) 0.08 ((0.14) 0.16 (0.15) 0.05 (0.14) Contrast sensitivity (OU) < (26.4) 76 (14.4) 1 (2.5) 455 (22.8) 1.5 to < (68.6) 404 (76.7) 26 (65.0) 1,412 (70.6) 1.2 to < (4.9) 44 (8.4) 13 (32.5) 127 (6.4) <1.2 2 (0.1) 3 (0.6) 0 (0) 5 (0.3) Mean (SD) 1.69 (0.13) 1.64 (0.14) 1.53 (0.13) 1.67 (0.13) UFOV subtest 2 (ms) <.0001 < (62.3) 225 (42.7) 8 (20.5) 1,125 (56.3) (30.4) 206 (39.1) 12 (30.8) 653 (32.7) > (7.4) 96 (18.2) 19 (48.7) 221 (11.1) Mean (SD) 142 (123) 209 (149) 322 (155) 163 (136) Trails B (min) <.0001 < (68.7) 253 (48.1) 7 (17.5) 1,241 (62.2) (31.3) 273 (51.9) 33 (82.5) 754 (37.8) Mean (SD) 2.34 (1.29) 3.03 (1.66) 3.47 (1.18) 2.55 (1.43) Notes: UFOV = Useful Field of View; SD = standard deviation. similar in that only a very small proportion of drivers more than 70 years old (0.3%) had contrast sensitivity at severe impairment levels (<1.2) that have been previously associated with increased MVC risk (18). It is interesting to point out that at the time of this study, the state in which this study took place (Alabama) did not have a vision rescreening policy in place. This means that participants visual acuity had not been screened for licensure because their initial application for licensure, when they were younger adults or when they moved into the state. Because almost all drivers had good visual acuity, this begs the question as to whether policies mandating vision rescreening at license renewal for older drivers are cost-effective and actually remove dangerous older drivers from the road. Only 2 out of 2,000 drivers had severe acuity impairment. Three previous studies on vision rescreening licensure policies for older adults report that these policies are associated with lower collision fatality rates (28 30), but another study did not find such a relationship except among the oldest old ( 85 years) (31). Regardless, though, no previous study has clarified whether it is the vision screening standard itself or going through the license renewal process in general that is the mechanism mediating any observed safety benefit. Research has established that older drivers with cognitive impairment are at an increased risk of MVC involvement and impaired driving performance (21,32 34). Even cognitive screening tests, such as the MMSE (16), which are relatively gross screens for cognitive dysfunction, are associated

6 572 OWSLEY ET AL. with impaired driving performance and increased crash risk in older drivers (35 37). Although the primary focus of this study was not on cognitive skills, it is still relevant to point out that 98% of this sample of drivers aged 70 and older had MMSE scores in the nondemented range ( 24), which is consistent with a previous large sample study of older drivers (38). Even for those in the 80s and 90s, 95% of these drivers had MMSE scores of 24 or higher. This suggests that the stereotypical view that many older adults who are licensed and actually drive, particularly those aged 80 and older, have serious cognitive problems is without basis. Cataract surgery and IOL implantation is highly effective at restoring vision due to aging-related lens opacities. This surgical procedure has also been shown to reduce MVC risk by 50% (13). It is thus noteworthy that almost half of this sample had already had cataract surgery and IOL placement. With each advancing decade, the percentage of drivers who had cataract surgery increased, with almost 85% of drivers aged 90 and older having undergone cataract surgery. The most prevalent visual disorder in this sample was slowed visual processing speed, as revealed by both Trails B and UFOV subtest 2; up to one third to one half of drivers in this sample had this visual processing impairment. This is concerning because slowed visual processing speed is a visual-cognitive screening test most consistently and strongly associated with increased crash risk in older drivers (21,38 40). It is worth pointing out that visual processing speed is not an ability that is screened for at licensing agencies in any jurisdictions in the United States (although two states have examined it on an experimental basis) (41,42). This study suggests that drivers aged 90 and older represent a very small percentage of the older adults behind the wheel, about 2%. It is interesting that although these persons are of very advanced age, in some ways they are healthier than drivers under the age of 90; however, given the cross-sectional nature of this analysis this, at least partly, reflects a survival bias. The results suggest that they tend to have fewer medical comorbidities, are less likely to have cataracts, and less likely to be previous or current smokers. On the other hand, they are more likely to have visual functional deficits than younger senior drivers in that they were more likely to exhibit slowed visual processing speed and have visual acuity worse than 20/40. Strengths and limitations of this study should be considered. This is the first population-based investigation of a comprehensive set of both visual sensory and higher order visual-cognitive processing screening tests in a large population-based sample of older drivers. Screening tests were selected based on their previously established relationships to MVC risk and impaired on-road driving performance. Second, the study incorporated a large sample of drivers (N = 2,000) and had inclusion criteria that insured that drivers were in fact licensed and actually had driven in the recent past. Limitations must also be acknowledged. The study was based on drivers in Alabama, and the generalizability of findings to other regions of the United States remains to be determined. Yet, there is little reason to suspect that older drivers in Alabama have characteristics significantly different than the rest of the United States. The researchers do not have information on the visual characteristics of the persons who were eligible but declined participation or those who they could not speak with on the phone to determine eligibility; it is possible that the nonparticipants visual characteristics have different distributional properties than those who participated. This is acknowledged as a study limitation. It might be argued that the nonparticipants were more likely to have visual impairments. Yet, previous research indicates that those who have visual impairments are more likely to be nondrivers and thus not eligible for a study focused on the visual characteristics of drivers (10,12). The study sample consisted of primarily whites and African Americans of non-hispanic descent, so the relevance of the researchers findings to the Hispanic, Asian, and other older driver populations in the United States remains to be determined. Although the researchers did not assess peripheral vision in this report, sensitivity throughout the visual field is being addressed in a further study. In conclusion, the researchers have described the visual sensory and visual processing characteristics of older drivers in a state where no visual acuity rescreening program for licensure renewal was in effect. However, what the researchers found is that even without such a visual acuity rescreening program, the prevalence of significant visual sensory impairment as measured by acuity and contrast sensitivity tests was very low, implying that many older adults with visual sensory impairment self-regulate themselves off the road and/or do so at the urging of their families, friends, physicians, or other health care providers. The researchers also found that the prevalence of slowed visual processing speed is quite high in the older driver population, which is concerning because it is not screened at reissuance of licenses for older adults, yet has been associated in several studies with elevated MVC risk (21,38,40). Further research will examine this sample prospectively in order to determine which visual screening tests are the strongest predictors of MVC risk in subsequent years. Funding This work was supported by the National Eye Institute and the National Institute on Aging of the National Institutes of Health (R01EY18966, P30AG22838); the American Recovery and Reinvestment Act of 2009; the EyeSight Foundation of Alabama; the Able Trust; and Research to Prevent Blindness, Inc. References 1. Friedman DS, O Colmain BJ, Muñoz B, et al. Prevalence of age-related macular degeneration in the United States. Arch Ophthalmol. 2004;122: Quigley HA, Vitale S. Models of open-angle glaucoma prevalence and incidence in the United States. Invest Ophthalmol Vis Sci. 1997;38:83 91.

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